Ranging or location awareness is a desirable feature in wireless networks, with applications ranging from military to safety, emergency (E911) and robotics. Research on the topic in wireless networks initially focused on outdoor cellular systems. These results were then extended to wireless local and personal area networks. Range estimation has received considerable attention in radar and sonar applications
Ranging is equivalent to estimating the time of arrival of a known signal with a narrow correlation function. It is known that the time resolution, and therefore the precision of range estimation, in any system is generally inversely proportional to the transmitted signal bandwidth.
Multi-band communication systems have been proposed for wireless personal area networks (WPANs). In a multi-band system where only a portion of the total bandwidth is available to any transmission, the resolution appears to be proportional to the inverse of the bandwidth of a sub-band. As a result, the resolution in a multi-band system may be inaccurately determined. In some previous systems, the estimates from different sub-bands is averaged in an attempt reduce the effect of noise. In view of the inaccurate determination of resolution in previous multi-band systems, there is a need in the art for the present invention.